Structural element with interlocking ribbing

Abstract

A structural element comprising opposed first and second, laterally and longitudinally extended, generally planar surface structures each having a closed figure pattern of ribbing projecting therefrom toward the opposite surface structure, the ribbing being of respective heights to bridge the space between the surface structures, the opposed ribbing being interlocked in registered, mating relation.

We claim: 
     
       1. Structural element comprising opposed first and second, laterally and longitudinally extended, generally planar surface structures each having a closed figure pattern of ribbing projecting therefrom toward the opposite surface structure, said ribbing being of respective heights to bridge the space between said surface structures, said opposed ribbing being interlocked in registered, mating relation. 
     
     
       2. Structural element according to claim 1, in which the first of said surface structures defines a ribbing projection of relatively greater height, and the second of said surface structures defines a ribbing projection of relatively lesser height. 
     
     
       3. Structural element according to claim 2, in which said second surface structure ribbing defines an outward edge groove into which the opposing outward edge of the first surface structure ribbing interfits in structural element defining relation.